Assembly Biosciences Inc

Assembly Biosciences has exercised its option to share 40% of U.S. development costs and profits for its herpes simplex virus helicase-primase inhibitor program under its collaboration with Gilead Sciences. The decision follows review of Gilead's complete development plan and budget for the program, which includes candidates GS-1179 and GS-5366. Gilead retains sole responsibility for further clinical development and commercialization, while Assembly Bio is eligible for up to $280 million in milestones and tiered royalties outside the U.S., with potential conversion to up to $330 million if certain opt-out rights are exercised. GS-1179 is expected to enter a Phase 2 trial in recurrent genital herpes by the end of 2026, with possible evaluation in combination with HIV pre-exposure prophylaxis. Assembly Bio's cash runway remains projected into 2029, including a $75 million collaboration extension fee from Gilead due in the fourth quarter of 2026.

Assembly Biosciences reported second quarter 2026 financial results and announced expansion of ABI-6250 into cholestatic liver diseases including primary biliary cholangitis and primary sclerosing cholangitis. The company completed a $115 million gross financing and projects cash runway into 2029, including the first $75 million Gilead collaboration extension payment due in the fourth quarter of 2026. Gilead selected GS-1179, formerly ABI-1179, to advance in the HSV helicase primase inhibitor program with Phase 2 initiation expected by year-end 2026. Net loss attributable to common stockholders was $3.9 million, or $0.20 per share, compared to $10.2 million, or $1.33 per share, in the same period last year. Cash, cash equivalents and marketable securities totaled $320.4 million as of June 30, 2026.